Dental chair



(No Model.)

3 Sheets-Sheet 1. A. W. BROWNE.

DENTAL CHAIR. No. 519,757. Patented May 15, 18%4.

WITNESSES (N0 Modem 3 SheetsSheet 2. A. W. BROWNE.

DENTAL CHAIR.

No. 519,757. Patented May 15, 1894.

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A. W. BROWNE.

DENTAL UHAI'R. No. 519,757. Patented May 15,1894.

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UNITED STATES PATENT OFFICE.

ARTHUR W. BROWNE, OF PRINCES BAY, NEW YORK, ASSIGNOR TO THE S. S. WHITE DENTAL MANUFACTURING COMPANY, OF PHILADELPHIA,

PENNSYLVANIA.

DENTAL CHAIR.

SPECIFICATION forming part of Letters Patent No. 519,757, dated May 15, 1894.

Application filed February 6,1894- Serial No. 499,281- (No model.)

To all whom it may concern.-

Be it known that I, ARTHUR W. BROWNE, a citizen of the United States, residing at Princes Bay, in the county of Richmond and State of New York, have invented certain new and useful Improvements in Dental Chairs; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to certain improvements, as hereinafter claimed, applicable to the well known Wilkerson dental chair for which United States Letters Patent were granted November 20, 1877, No. 197,441.

In my application for United States Letters Patent, Serial No. 499,051, filed February 5, 1894, improvements are shown corresponding with or more or less nearly resembling some of the devices illustrated and described in connection with my present invention. I do not herein claim any improvement set forth in my said application.

In the accompanying drawings which show all features of a Wilkerson chair needed for proper illustration of a suitable embodiment of my inprovements, Figure 1 is a view partly in elevation and partly in vertical section on the line 1 of Fig. 3. Fig. 2 is a View partly in side elevation and partly in vertical section in different planes, with parts omitted. Fig. 3 is a view partlyin plan and partly in horizontal section on the line 3 of Fig. 2. Fig. 4 is a view partly in elevation, and partly in section on the line 1 of Fig. 3. Fig. 5 is a view in perspective showing details of construction. H

A hollow base or pedestal A provided with supporting legs, has attached to its lower end a liquid-carrying reservoir A. A hollow cylinder B is fitted to rest upon and turn within the pedestal. A clamp screw operated by a lever B serves to lock the hollow cylinder against turning in the pedestal, and a chair body support or plunger 0 is vertically adjustable in the cylinder. This support 0 is formed with a vertical groove or recess provided with a row of rack teeth a. Suitable packing at the lower end of the support serves to fit liquid-tight within the cylinder B. At its lower end the cylinder is provided with a screw-attached cap D which has a central opening or liquid passage above which (within the cap) is a loose or float valve d opening upwardly and hereinafter termed the inlet valve. A downwardly opening valve (1 (hereinafter called the outlet valve) upon which a spring I) acts with a tendency to close it or hold it up to its seat, is located in a chamber D at the side of the cylinder and having communication by way of a liquid passage 6 with the cylinder below the chair body support 0. The chamber D' also has communication with the liquid reservoir A when the outlet valve d is open. The liquid way or passage controlled by the inlet valve is of much greater area, it will be seen than the liquid way or passage 6 through which liquid is allowed to flow only-when the outlet valve is open.

With the exceptions of modifications, such as will readily be understood, in the reservoir and the cylinder, and in the construction and arrangement of the valve mechanism, all the parts so far as in detail briefly described above are the same as set forth in the before-mentioned Patent No. 197,441; and the modified valve mechanism and other parts above described perform the same functions as explained in said patent.

A foot-actuated elevating lever made in sections jointed together serves to elevate the chair body support as in the Wilkerson patent referred to, and is made to serve, also, as the means through or by way of which the chair body support may be clamped against lateral movement in any position to which it may be adjusted, and the outlet valve tripped to permit of gradual descent of this support, as in turn to be explained. Said elevating lever is made in two parts orsections-a main or outer part E and a short inner partE-- which are jointedtogether by a vertical pivot F passing through lugs or forks ff of the inner section and through the inner end of the outer section of the lever near a horizontal pivot g by which the lever is jointed by its inner section to the cylinder B which is provided with lugs G G engaged by this pivot sections L L.

g. It will be seeuthat the lever (both sections thereof) is adapted to rock or swing vertically and that the long arm or main section of the lever may be swung horizontally to one side; A stop h within the cylinder is engaged by a lug H at the inner extremity of the lever to limit downward movement of the outer arm of the lever. The inner end or short arm of the lever is curved about the chair body support and provided with a pivoted pawl I for engaging the rack teeth of the support, and a spring I secured at its opposite ends to the pawl heel and the cylinder, serves to cause engagement of the pawl with the rack teeth when the main section of the lever is depressed by downward force applied to its foot rest J. The pawl is normally held out of engagement with the rack teeth by the contact of a shoulder is on the pawl with a projection is on the cylinder. The projec tion It projects into the longitudinal recess of the chair body support to keep it from turning in the cylinder. The operation of the spring-actuated pawl is fully set forth in the above-referred-to patent; and as explained in said patent, when the chair body support is elevated by working the elevatinglever the inlet valve opens automatically so as to allow 4 liquid from the reservoir to follow the support and uphold it in its position of adjustment when the outlet valve is closed; while when this outlet valve of the upholding mechanism is tripped or opened the support is allowed to gradually descend by the flow of the liquid from beneath'the support back to the reservoir.

To clamp the support against lateral movement or vibration in any position to which it may be adjusted, the main arm of the elevating lever is provided at its inner end with a cam Z which when-the long arm of the lever is moved sidewise into the position in which it is represented by dotted lines in Fig. 3, acts upon a clamping shoe made in two parts or This manner of clamping the support is substantially the same as fully set forth in my above -mentioned application. When the clamping shoe is actuated by the elevating lever a lateral lug M on the main arm of the lever rests between projections m m of the cylinder lug G thus preventing movement of the lever either upwardly or downwardly, and guarding against actuation of either the support or outlet valve.

When the main arm of the elevating lever occupies its normal position it is prevented from swinging sidewise in one direction by a lateral projection s at its inner end which comes in contact with a projection f of the inner section of the lever.

Provision is made for tripping the outlet valve of the mechanism for upholding the support, so as to allow the support to descend by escape of the liquid from beneath it, in the following way: A thrust rod N guidedin its endwise movements by guide-way lugs '11 n on the cylinder, through which lugs it passes, is yieldingly held in its normal or most elevated position by means of a spring P bearing at one end against a collar 19 on the rod and at its opposite end against the lower guide way lug n. The collar p limits upward movement of the thrust rod by coming in contact with the upper guide-way lug n.

The thrust rod is adapted to bear at its lower end upon the stem of the outlet valve so as to depress and open this valve when the rod is actuated by the elevating lever by pushing upward its outer end by the foot to forcibly rock the inner end of the lever downward. The thrust rod, by the action of its spring P, is also made to serve as a stop to limit upward movement of the main section of the lever until it is pressed upward by the foot with sufficient force to overcome the force exerted by the-thrust rod spring.

I claim as my invention-- 1. The combination, in a dental chair, of the vertically adjustable support, the cylinder having the lever pivoting lugs one of which is provided with two projections, the elevating lever pivoted to said lugs, composed of jointed sections and provided with the cam and lateral lug, and the clamping shoe for locking the support against lateral movement, 9

the horizontaliy rotating cylinder, the liquidcarrying reservoir, the vertically adjustable support mountedin the cylinder and provided with the rack teeth, the vertically rocking sectional elevating lever pivoted by its inner section to the cylinder, the pawl carried by said section and adapted to engage the rack teeth of the support upon downward movement of the outersection of the lever, the outlet valve by which liquid is allowed to pass from the cylinder beneath the support to the reservoir, the thrust rod actuated by the lever upon forcible upward movement of the outer section thereof to trip the outlet valve,

and the spring acting upon the thrust rod to hold it up when not forcibly depressed by the action of the lever, substantially as and for the purpose set forth.

In testimony whereof I afiix mysignatu re in presence of two witnesses.

ARTHUR W. BROWN E.

Witnesses:

ELI T. STARR, EDW. F. SIMPSON, Jr. 

